Rehab and surgical techniques after an (anterior) cruciate ligament injury have developed and improved significantly in recent years. Yet re-injury rates and the share of people who don't return to…
Rehabilitation and surgical techniques after an (anterior) cruciate ligament injury have developed and improved significantly in recent years. Nevertheless, re-injury rates and the share of people who don't return to their previous level (especially young athletes) remain unsatisfactory and unacceptable [1,2,3,4]. Building on these findings, a good rehab process with a well-planned long-term structure and a detailed, sensible RTS test battery at the end is very valuable for bringing athletes back to a high-performing, stable level in the best possible way.
Today, new aspects such as psychological readiness, or fear of movement in general or of practising one's own sport or competing, are becoming increasingly important and valued [5,6]. This adds further nuance to the pure strength and mobility tests of older RTS batteries and continues to change the course of rehabilitation. Additional aspects such as the social environment and other environmental factors have also become more important. However, these can hardly be influenced directly in the therapy process, so they are not discussed further in this article.
Alongside these developments, the question of time until return to sport is being discussed more critically, while very sport-specific preparation is seen as increasingly important [8,9,12]. Such specific preparation often takes quite some time and therefore usually exceeds the time and logistical framework of a typical physiotherapy rehab process (in-house rehab). Yet regaining full confidence on the pitch is a decisive factor, especially for athletes who want to fully return to their sport. Aspects that may play a role in a sport-specific context include footwear, playing surface, possible opponent contact disrupting a movement, fatigue and general distraction from external factors, as well as additional objects that have to be moved. Testing and practising these situations is often impossible in physiotherapy alone, and athletes are often only given independent tasks to do at home. But further coaching and support in exactly this phase – when more variation and dynamics are meant to come in – can be very important for many athletes, not least to feel safe and prepared.
A paper by Gokeler et al. [7] takes a closer look at the general RTS situation. The authors present 10 points that could be particularly relevant for a successful return to sport with a low risk of recurrence. These include individually tailored surgery, rehab with sensory and cognitive challenges and, precisely, sport-specific loads.
However, most current test batteries and rehab processes in the RTS context fall short on these latter factors and may therefore not fully reflect complex loads and demands, such as reacting to unpredictable actions. As a result, athletes may not be optimally prepared for their return to sport, which may be one reason for the higher re-injury rates. This is exactly where so-called on-field rehabilitation (OFR) can come in and close this important gap in the recovery process.
What is on-field rehabilitation?
Put simply, OFR is training that closes precisely the gap between physio (indoors) and full-intensity team training (outdoors) [8,9]. Below, this concept is presented in a little more detail and explained with an example.
The idea of OFR was first described by Della Villa [10] in 2012. OFR started with 50 footballers about 90 days post-op and led to improvements in the KOOS questionnaire, leg strength and endurance. The OFR process usually goes through 5 phases that prepare athletes for increasingly demanding and typical situations (e.g. with opponent contact, reactive etc.). These demands are both physical/mechanical and (neuro)cognitive in nature.
A major focus is on planning and progressing variable demands/movement patterns and the load they place on athletes [11].
Such an OFR programme, however, already requires a good level of strength, movement quality and mobility, and the following criteria should be met before OFR can start:
- No knee pain and no swelling
- No subjective feeling of instability
- Negative knee laxity test
- At least 80% strength symmetry (extension & flexion)
- Good movement quality in basic movements
- Sufficient endurance (approx. 10 min. at 8 km/h)
The 5 phases of OFR
Using football – or the RTS towards it – as an example, the 5 phases of OFR are briefly outlined here (based on [9]).
Phase 1: is marked by the start of linear movements on the pitch. The primary goal is to increase intensity (= movement speed) while keeping movement quality (= execution) high. At first this is done without a ball and without an opponent (higher variation/risk). These movements can also be lateral and are initially performed at a speed chosen by the athlete (shared decision).
Phase 2: is characterised by the start of multidirectional movement patterns, such as figure-8 runs or curved runs, plus more intense braking and acceleration. The patterns and exercises from phase 1 can/should now be performed at almost maximum speed.
Phase 3: is the next stage, characterised above all by more sport-specific exercises and exercises with a reactive component (ball, partner). Previous tasks may now become more complex, and overall volume should also increase to come closer to the workload of a full training session.
Phase 4: is when almost full opponent contact (1v1 at approx. 85%) can be reintroduced, and more complex multidirectional patterns are practised at almost maximum speeds. General loads, including in athletic training, should now be very intense and at relatively sport-specific full volumes (> 5 km total distance, approx. 300 m of sprint distance in total, 20 min. of continuous load above 85% HRmax).
Phase 5: describes the final phase, in which full training loads and volumes are reproduced and practised with and without prior fatigue. The goal here is to replicate normal training as closely as possible, with almost no restrictions on directions, intensities, opponent contact etc.
The 4 pillars of OFR
- Keeping movement quality stable (in unforeseen situations) – body position in space, knee angle/valgus, hip movement etc.
- Physical conditioning, both aerobic and anaerobic – the sport's specific demand profile is key
- Relearning sport-specific skills and technique – technical and tactical with more complex options, individually or in small groups, with and without opponent pressure, reflecting on what was practised
- Accumulating a typical training workload – volumes and intensities, taking the acute-to-chronic workload ratio into account
These are decisive factors that determine further development in the later rehab and RTS process. To prepare athletes even better for competition with unpredictable situations, training should – as mentioned above – involve gradually increasing uncertainty and less predictable situations.
In the specific example of football, cleanly executed braking movements [13,16] and changes of direction (CoD) [14] can and should be practised on the pitch, as these are essential situations in which extremely high forces can act [11]. Mastering these loads in terms of volume, intensity and technique is an essential foundation for preparing the final step, return to competition (RTC).
A possible model for progressing these tasks was presented in 2022 [12].
The final step: the RTS test battery
The last step at the end of an RTS process, however, is always a well-thought-out RTS test battery, supplemented by the sensible use of questionnaires (KOOS, RSI or similar). Only when athletes have gone through this process well, with their own sense of safety and confidence, and the result of the final testing is satisfactory, should they fully return to sport-specific training and competition.
Sources
[1] Ardern CL, Taylor NF, Feller JA, Webster KE (2014) Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. Br J Sports Med 48:1543–1552
[2] Paterno MV, Rauh MJ, Schmitt LC, Ford KR, Hewett TE (2012) Incidence of Contralateral and Ipsilateral Anterior Cruciate Ligament (ACL) Injury After Primary ACL Reconstruction and Return to Sport. Clin J Sport Med 22:116–121
[3] Webster KE, Feller JA (2016) Exploring the High Reinjury Rate in Younger Patients Undergoing Anterior Cruciate Ligament Reconstruction. Am J Sport Med 44:2827–2832
[4] Webster KE, Hewett TE, Feller JA (2021) Anterior Cruciate Ligament Injuries in Australian Rules Football: Incidence, Prevention and Return to Play Outcomes. Open Access J Sport Med 12:33–41
[5] Ardern CL, Taylor NF, Feller JA, Whitehead TS, Webster KE (2013) Psychological responses matter in returning to preinjury level of sport after anterior cruciate ligament reconstruction surgery. Am J Sport Med 41:1549–1558
[6] Truong LK, Mosewich AD, Holt CJ, Le CY, Miciak M, Whittaker JL (2020) Psychological, social and contextual factors across recovery stages following a sport-related knee injury: a scoping review. Br J Sports Med 54:1149–1156
[7] Gokeler A, Grassi A, Hoogeslag R, et al. Return to sports after ACL injury 5 years from now: 10 things we must do. J Exp Orthop. 2022;9(1):73. doi:10.1186/s40634-022-00514-7
[8] Buckthorpe M, Della Villa F, Della Villa S, Roi GS (2019) On-field Rehabilitation Part 1: 4 Pillars of High-Quality On-field Rehabilitation Are Restoring Movement Quality, Physical Conditioning, Restoring Sport-Specific Skills, and Progressively Developing Chronic Training Load. J Orthop Sport Phys Ther 49:1–5
[9] Buckthorpe M, Della Villa F, Della Villa S, Roi GS (2019) On-field Rehabilitation Part 2: A 5-Stage Program for the Soccer Player Focused on Linear Movements, Multidirectional Movements, Soccer-Specific Skills, Soccer-Specific Movements, and Modified Practice. J Orthop Sport Phys Ther 49:1–6
[10] Della Villa S, Boldrini L, Ricci M, et al. Clinical Outcomes and Return-to-Sports Participation of 50 Soccer Players After Anterior Cruciate Ligament Reconstruction Through a Sport-Specific Rehabilitation Protocol. Sports Health. 2012;4(1):17-24. doi:10.1177/1941738111417564
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